A conventional ultrasonic type liquid atomizing apparatus has a liquid atomizing construction as an example, as shown in FIG. 17. A liquid atomizing construction shown herein includes: a liquid reservoir section (a bottle) 70 reserving a liquid (a chemical liquid) L; an ultrasonic pump (a horn oscillating member) 77; and a mesh member 80. Horn oscillating member 77 is constructed of: a pipe 74 having liquid-suction through holes (water suction holes) 73 extending along an axial direction, and communicating from a lower end 71 located in bottle 70 to an opening provided at the top end 72 located outside bottle 70; and two annular oscillating members 75 and 76 mounted to pipe 74. Mesh member 80 is mounted to pipe top end 72 in contact therewith using an elastic member (not shown) such as a coil spring.
In such a liquid atomizing construction, a high frequency voltage generated by an oscillator 78 is applied to annular oscillating members 75 and 76, thereby causing annular oscillating members 75 and 76 to be ultrasonically oscillated and to oscillate pipe 74 upward and downward. With such a working, chemical liquid L in bottle 70 is sucked up from lower end 71 of pipe 74 through water suction holes 73 to come out of the opening of top end 72. Chemical liquid L is atomized away in a state of a fog by means of the mesh member 80 mounted to top end 72 in contact therewith.
In a liquid atomizing apparatus having the above liquid atomizing construction, however, a necessity exists for providing fine water suction holes for sucking up the chemical liquid into the pipe with an accompanying problem of much expenses in time and labor, and therefore increase in cost, in manufacturing aspect.
On the other hand, a liquid atomizing construction different from the above construction has been contrived in which pressure means such as a piston pressurizing a chemical liquid in a bottle is provided instead of a pipe having the above water suction holes, whereby the chemical liquid reserved in the bottle is little by little fed to an atomizing section (a contact section between the top end of the horn oscillating member and the mesh member).
Even a liquid atomizing apparatus equipped with a liquid atomizing construction of this kind, however, requires means operating pressure means, a structure linking both means, electrical interconnection and others separately in addition to the pressure means pressurizing the bottle. Therefore, problems have also arisen in reliability and operability in addition to a fault of complexity in feed means leading to high cost.
In the mean time, in a case where any of the above liquid atomizing constructions is adopted, while the mesh member is pressed onto the end surface of the distal end of the horn oscillating member by a force with a proper magnitude, a chemical liquid gathered in the proximity of the mesh member is leaked out onto the front surface and the periphery of the mesh member, and the leaked chemical liquid contaminates the outer surface of the apparatus and is hardened thereon to thereby hinder oscillation of the mesh member, thus having resulted in problems such as poor atomizing performance. What's worse, a need arises for carefulness so as to limit a chance of excessive inclination of the apparatus to the lowest probability, which has made handling of the apparatus difficult.
Moreover, in a liquid atomizing apparatus atomizing a chemical liquid using a mesh member, the chemical liquid is gathered in fine pores of the mesh member and is jetted in a state of a fog from the fine pores under pressure; therefore, fine pores 81 and 82 of mesh members 80A and 80B, as shown in FIGS. 18 and 19, have a step profile and a tapered profile, respectively, ea so as to be formed narrower toward the discharge side of liquid droplets 83 and wider in the surface side (the lower side in the view from above in the figure) thereof in contact with horn oscillating member 77 in longitudinal section.
Mesh members 80A and 80B are important factors in determination of an atomizing performance of a liquid atomizing apparatus, but acting as a main cause for clogging and degradation in performance of the mesh. For the purpose of raising a density of fine pores 81 or 82 is useful in order to enhance an atomizing efficiency, but with a distance between fine pores 81 or 82 made shorter with the result that degradation in strength of a mesh member occurs and droplets 83 jetted to outside, as shown in FIG. 18, lose directivity thereof to aggregate into dew drops 84 of large diameters. As shown in FIG. 18, droplets jetted to outside are attached back onto the atomization surface (the front surface) of mesh member 80A to form a film 85 thereon and therefore, liquid drops of large diameters fly away to the air, kinetic energy of atomization is lowered or the like inconvenience arises as problems.
It is, therefore, a first object of the present invention to simplify a feed structure for a liquid from a liquid reservoir section to an atomizing section, and it is a second object of the present invention to provide a liquid atomizing apparatus realizing no leakage of a liquid regardless of a degree of inclination thereof.
It is a third object of the present invention to provide a liquid atomizing apparatus, on one hand, realizing fine pores at a high density without causing degradation in strength, while, on the other hand, having a mesh member preventing liquid droplets from aggregating into a liquid drop and being attached onto an atomization surface.